新型方向性自差分涡流传感器的仿真设计与研究

Design and Research on Simulation of a New Directional Self-difference Eddy Current Sensor

传统涡流检测技术采用一个圆柱形的激励线圈来产生激励磁场,通过用检测线圈来收集扰动磁场,然而由于激励线圈引起的磁场要比缺陷引起的扰动磁场强很多,这种结构的传感器对缺陷的检测灵敏度低,需采用差分的方法来获取缺陷信息。提出了一种新型涡流传感器,其通过采用矩形激励线圈来改变激励磁场的空间分布,使得无需采用差分方法就可以获得缺陷信息。在对新型传感器进行原理分析的基础上,仿真分析了其与传统传感器探头缺陷检测灵敏度之间的差异。并对传感器尺寸和激励频率进行了优化设计,最后验证了该新型传感器对缺陷长度的定量检测能力。仿真结果表明,该新型传感器具有较高的检测灵敏度和缺陷定量精度,为以后单激励多检测阵列涡流传感器的研究奠定了基础。

Traditional eddy current testing technology generate a magnetic field excitation by a cylindrical excitation coil, and collect magnetic field perturbations through the detecting coil, however, the magnetic field generated by excitation coil is much stronger than those generated by defect, so the defect detection sensitivity of the sensor with this structure is not high, and it is necessary to adopt difference methods to obtain the information of defect. A new type of eddy current sensor is proposed, which can he used to change the spatial distribution of the excitation magnetic field by using the rectangular excitation coil, so that the defect can be quantified without difference. Based on the analysis of the principle of the new sen- sor, the sensitivity difference between the traditional sensor and the defect detection is analyzed by simula- tion. The sensor size and excitation frequency were optimized, and the quantitative detection ability of the new sensor was verified. Simulation results show that the new sensor has high detection sensitivity and de- fect quantitative accuracy. To lay the foundation for the research of single excitation and multi detector array eddy current sensor.